European Space Agency is preparing to wake up its most ambitious space craft ahead of a mission to land on a comet.
The Rosetta space craft was launched in 2004 to track and chase after a comet, and has spent more than two years in 'hibernation' to conserve power.
Now the space agency has set an alarm - literally - for 10 am on Monday, and hopes that the craft will activate on time.
If successful, the probe will send an "I'm awake" message back to Earth and start the process of travelling to its rendezvous point with the Comet 67P/Churyumov-Gerasimenko.
If all goes well, Rosetta will collect data about the 4km-wide comet from August until October, and then try to drop a small robot onto its surface.
Rosetta is currently located about 673 million km from the Sun, but has already made five round trips around our star in order to pick up the energy needed to line up with its final destination.
On its blog ESA has lots of details about exactly what it's hoping to hear from Rosetta, as well as the schedule for today's events (hopefully), and tools to work out how far from the Sun it really is.
Here's the rough schedule:
- 9:15am: ESA live-broadcast starts
- 10am: ESA sends its wake-up call to Rosetta
- 10:45am: Rosetta receives call
- 4pm: Rosetta fires thrusters to stop slow-rotation
- 4pm: Rosetta checks solar arrays to ensure power supply
- 4.45pm: Rosetta sends 'I'm awake message back to Earth'
- 5:30pm: Earth receives Rosetta's message
ESA is also broadcasting the wake-up call live: